For the second year in a row, I'm having a problem with flies all over the snail vine plant that grows on my trellis and front gate. It's an especially big problem because it's right outside my front door and the flies get in the house and annoy my upstairs neighbor. Last year I got some ladybugs to eat the aphids that seemed to attract the flies, but even after the aphids were gone, the flies remained. I tried hosing down with plain water and it didn't help. I don't want to use an insecticide because I don't want to kill the other insects that aren't causing the problem, and also because 'possums, raccoons, cats, skunks, etc. climb over the vine-covered gate and birds land on it, and I don't want to make them sick. Any suggestions for a natural spray that won't hurt anybody but will clean off whatever is attracting the flies?
House Flies Swarming Snail Vine
Certified GKH Gardening Expert
Flies are normally attracted to the honeydew left behind from pests, like aphids. I would treat the vine with neem oil, as this is effective against most pests (especially aphids) but is perfectly safe for beneficial insects, animals and birds (as well as you). Here is more information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm